Air operated evacuation system



y 1969 G. K. AUSTIN, JR 3,452,751

AIR OPERATED EVACUATION SYSTEM Filed Nov. 12, 1965 Sheet of 2 VACUUM I FLOW EXHAUST AIR FILTER 60 AIR, WATER a SOLIDS SEPARATOR SOLIDS LL COLLECTOR WATER TO WASTE LINE INVENTOR GEORGE K. AUSTIN Jr.

MIIE WITL QIQMEQM ATTORNEYS July 1, 1969 e. K. AUSTIN, JR 3,

AIR OPERATED EVACUATION SYSTEM Filed Nov. 12. l965 Sheet 2 of 2 ATTORNEYS United States Patent 3,452,751 AIR OPERATED EVACUATION SYSTEM George K. Austin, .Ir., P.(). Box 111, Newberg, Oreg. 97132 Filed Nov. 12, 1965, Ser. No. 507,324 Int. "Cl. A61m J/00; F04f 5 /48, 5/00 U.S. Cl. 128-277 5 Claims ABSTRACT OF THE DISCLOSURE This invention relates to an air operated evacuation system and more particularly to improved apparatus for evacuating water and debris which accumulates in the mouth of a dental patient during the practice of highspeed dentistry using the washed-field technique.

Previously known types of apparatus useful for practicing this dental technique include the use of a motor-fan air evacuation unit similar to a conventional household vacuum cleaner. Such units are utilized to draw a suction, or produce a negative pressure, in a fluid conducting line which has an intake end adaptable for being held in the mouth of a dental patient. Such previously known apparatus relies upon the motor-fan air evacuation unit to cause wash water and debris to be entrained in a large volume flow of air and be moved through the fluid conducting line to waste by the action of negative pressure created by the motor-fan evacuation unit.

It is a primary objective of this invention to provide a novel type of evacuation apparatus wherein a Venturi is located closely adjacent the intake end of the fluid conducting line and the flow of actuating air to the Venturi produces a low positive pressure from the Venturi to the outlet end of the fluid conducting line thereby substan tially reducing the amount of air intake at the intake end of the fluid conducting line. Accordingly, the present invention reduces the amount of atmospheric air which is drawn into the patients mouth thereby reducing the amount of atmospheric dust deposited upon the moist tissues of the patients mouth and also reducing dehydration of such moist tissues.

Another object of this invention is to reduce the length of travel, under a negative pressure, for the material which is being evacuated.

Another object of this invention is to provide regulating means for varying the inflow of air at the nozzle of the fluid conducting line.

Another object of this invention is to eliminate the vacuum line pulsations commonly found in prior art devices.

Another object of this invention is to provide an improved evacuation apparatus in combination with a conventional dental unit wherein the pressure control valve is conveniently mounted upon the dental unit and the downstream end of the fluid conducting line is conected to the detal unit drainage system.

Another object of this invention is to provide evacuation apparatus which includes an actuating valve having a novel construction and being located closely adjacent to the intake end of the fluid conducting line.

A further object of this invention is to provide a novel combination of a high pressure gas line and a low pressure fluid conducting line wherein the high pressure gas line is disposed within the low pressure fluid conducting line whereby inadvertent rupture of the high pressure gas line would create no hazard to persons or related equipment.

It is to be understood that while the present invention is described with particular reference to dental or surgical procedures, the invention is not limited to use in such fields, since other related uses will become readily apparent to those skilled in the art.

With the above and other objects in view which will hereinafter appear, the nature of the invention will be clearly understood by reference to the following and detailed description, the appended claimed subject matter and the several views illustrated in the accompanying drawings.

In the drawings:

FIGURE 1 is a fragmentary perspective view illustrating the major components of the present invention mounted upon the cuspidor arm of a conventional dental unit.

FIGURE 2 is a diagrammatic view, partly in section, illustrating the evacuation apparatus contemplated by the present invention.

FIGURE 3 is an enlarged cross-section of a novel hand piece illustrating the finger tip valve in the non-operating position.

FIGURE 4 is a fragmentary section showing the finger tip valve in the depressed or operating position.

Referring to the drawings in detail, the invention relates to a novel evacuation apparatus, generally indicated by the numeral 10, which is shown for illustrative purposes as being usable in combination with a conventional dental unit, generally indicated by the numeral 12. The dental unit 12 is preferably of the type provided with a cuspidor arm 14 and a cuspidor 16.

A fluid conducting line 18 includes a hand piece 20 at the intake end thereof and is provided with an intake nozzle 22. The intake nozzle 22 is small enough in size to be insertable within the mouth of a dental patient at the same time that a dentist is performing a drilling or surgical operation.

Incorporated within the hand piece 20 is a Venturi, genally indicated by the numeral 24 and clearly shown in FIGURES 2-4. The Venturi 24 includes a small diameter open portion 25 located at the upstream end thereof and an enlarged diameter open portion 26 located at the downstream end thereof. An actuating valve, generally indicated by the numeral 27, is located in the hand piece 20 and is disposed intermediate the intake nobble 22 and the Venturi 24. The actuating valve 27 includes a tubular housing 28 transversely disposed within the hand piece 20 and having a jet opening 29 on a side thereof directed toward the Venturi 24. A plunger 30 is slidably mounted within the housing 28 and is provided with a pair of O-rings 31 and 32. The plunger 30 is provided with a push button 33 having a collar 34 disposed within a recess 35 in the hand piece 20. A high pressure gas line 36 has one end thereof attached to the tubular housing 28 by a hollow stem 37 and a suitable screw-threaded coupling 38. A flow of high pressure gas through the line 36 will, as is best shown in FIGURE 3, force the plunger 30 to the left so as to cause O-ring 31 to be seated within the tubular housing 28. As is shown in FIGURE 4, when the push button 33 is depressed the O-ring 31 is moved into a cavity 40 and becomes unseated from the tubular housing 28 so that high pressure gas flowing through the line 36 and housing 28 exits through jet opening 29 and is directed through Venturi 24 downstream from the intake nozzle 22. Accordingly, a partial vacuum or negative pressure, i.e., pressure below atmospheric pressure, is created in the intake nozzle 22 upstream from the actuating valve 27. The intake nozzle 22 is attached to the hand piece 20 by a suitable plastic fitment 41 and a sealing fit is established between the nozzle 22 and the fitment 41 so that atmospheric air, liquids and small solids are sucked into the nozzle 22 and are drawn downstream past the actuating valve 27 by the action of the partial vacuum. After the air, liquids and solids pass the actuating valve 27 they are forced downstream through the Venturi 24 and line 18 by a positive pressure, i.e., above atmospheric pressure, which is produced by the air or other gases which enter the Venturi through the high pressure gas line 36 and jet opening 29. Thus, the matter drawn into the apparatus gets an added push by low positive pressure from the jet opening 29 completely through the fluid conducting line 18.

The evacuation apparatus is preferably operated by high pressure air but other compressed gases, such as carbon dioxide, can also be used. In the preferred form of the invention, the high pressure gas line 36 has a first line portion 42 connected to a high pressure air supply (not shown) such as a suitable air compressor. A control and shut-off valve 43 is located in the line portion 42 and is preferably mounted upon the cuspidor arm 14 so as to be conveniently located adjacent a mounting bracket 44 for hand piece 20.

A fitting 46, as is shown in FIGURE 2, is provided for connecting line portion 42 to the high pressure gas line 36. As is clearly apparent from FIGURES 2 and 3, the apparatus 10 is provided with a safety feature wherein the high pressure gas line 36 is contained within the fluid conducting line 18 from the fitting 46 to a fitment 47 located adjacent the upstream end of the line 18. The fitment 47 has a pair of openings formed therein and provides a seal-fit with the Venturi portion 24 of the hand piece and with the high pressure gas line 36.

An air, water and solids separator, generally indicated by the numeral 50, is connected to the downstream end of fluid conducting line 18 by a drain tube 52. The separator 50 includes an upper portion 53 and a lower portion 54 which are detachably connected together, at 55, by a conventional screw-coupling or bayonet joint or may be clamped together by a gravity-actuated latch member 56.

The discharge portion of drain tube 52, located within the separator 50, is directed downwardly toward a drain and waste line 58. It is desirable that a screen member or solids collector 60 is disposed within the lower portion 54 in order to trap large solid particles, such as gold inlays, which may inadvertently be drawn into the intake nozzle 22 during a dental operation.

The upper portion 53, of the separator 5d, is equipped with an outlet tube 62. so as to be placed in fiuid communication with an exhaust air filter 64. Thus, air entering the apparatus at the intake nozzle 22 and at the actuating valve 27 is exhausted at the filter 64, while liquids and small solids are passed to waste through line 58.

The evacuation apparatus 10 is operated by high pressure air, or other gas, entering at the supply inlet such that the pressure may be regulated at the control and shut-oif valve 43 so that air at a constant pressure is delivered by line portion 42 and line 36 to the actuating valve 27. The high pressure air cannot pass O-ring 31 until the plunger is depressed by a force upon push button 33. When the push button 33 is depressed the O-ring 32 prevents the air from escaping through the recess and around the collar 34. Thus, the high pressure air is directed outwardly through jet opening 29 and passes downstream through the Venturi 24 so as to create a partial vacuum or negative pressure in the intake nozzle 22. Atmospheric air rushes into intake nozzle 22 and will entrain therein liquids and solids which are to be disposed of. As such material passes the actuating valve 27 it is introduced to a positive pressure as a result of the expansion of the high pressure air fed into the system through the line 36. The air, liquids and solids pass through the fluid conducting line 1-8 and drain tube 52 and are separated at the separator 50 such that the air is exhausted through filter 64 and the liquids and small solids pass through the screen 60 and into the drain and waste line 58. Large solid materials are separated from smaller solid material and liquids by the screen 60. The large solids may be removed from the lower portion 54 by disconnecting the lower portion from the upper portion 53 at the connection 55.

A typical set of operating data for a commercial embodiment is set forth in the following table:

Water Vac. air Air lino ejected, flow at pressure, cc. per nozzle, lnput, V ortox, p.s.i.g. second c.1'.rn. c.l.n1. in.

1O 0. 9 1. 6 07 20 5 2. 9 1. 1 i 2 30 11 3. 9 1. 5 95.2 2.3 40 18 5. 2 1. 8 M 3.0 50 25 '6. 1 2.1 %2 3.7 60 30 6. 7 2.4 340 4.6 70 35 7. 0 2. 6

The above data were compiled while using an intake nozzle 22 which had an internal diameter of inch. Air pressure in the high pressure gas line 36 was varied in increments of 10 p.s.i. from zero to 70 p.s.i.g. A desirable operating pressure, both from the standpoint of efficiency and the use of relatively low pressures for safety purposes is 40 p.s.i.g. At this recommended pressure the apparatus develops a static vacuum of 2.3 inches of mercury, which value is well below that which would cause pain to a patient if the intake nozzle 22 were to come in contact with tissue.

Using the washed field technique of dentistry, a stream of cleansing liquid is projected upon the operative field in order to control temperature at the drilling bit and to wash away debris. It has been established that the capacity of a patients mouth is approximately cubic centimeters per minute. As is indicated by the above table the apparatus of the present invention is capable of ejecting 18 cubic centimeters of cleansing liquid per second when operating at the recommended air pressure of 40 p.s.i.g. It is readily apparent that the present apparatus is capable of ejecting over 1,000 cubic centimeters of cleansing liquid per minute while vacuum air flow at the nozzle 22 is held at a relatively small flow of 5.2 cubic feet per minute as compared to known types of apparatus which require an air flow in excess of a 8.0 cubic feet per minute.

What is claimed is:

1. Evacuation apparatus comprising a fluid conducting line having an intake end and a downstream end, a Venturi disposed within said fluid conducting line adjacent the intake end, means for directing a flow of gas through said Venturi away from said intake end toward said downstream end to produce a negative pressure upstream from said Venturi, said downstream of said fluid conducting line being provided with a separator device for separating air from liquids and solids, said separator device including means for connecting said device to a waste line and a solids collector screen disposed for preventing passage of large solids into said waste line, and an exhaust air filter mounted adjacent a top portion of said separator device for filtering air received from said fluid conducting line and precluding discharge of liquids and solids therethrough.

2. Apparatus as defined in claim 1 wherein said separator device includes means for detachably coupling the top portion of said device to the bottom portion of said device.

'3. Evacuation apparatus comprising a fluid conducting line having an intake end and a downstream end, a Venturi disposed within said fluid conducting line adjacent the intake end, and means for directing a flow of gas through the Venturi away from said intake end toward said downstream end to produce a negative pressure upstream from said Venturi, the improvement comprising said evacuation apparatus in combination with a.

dental unit and a source of compressed gas, a gas pressure control valve mounted on said dental unit and connected to said source of compressed gas, and a high pressure gas line having a first portion leading from said gas control valve to said fluid conducting line adjacent the downstream end thereof and a second portion disposed within said fluid conducting line and extending from adjacent said downstream end to adjacent said intake end, and valve means connected to said second portion of said gas line at the upstream side of said Venturi.

4. Evacuation apparatus comprising a fluid conducting line having an intake end and a downstream end, a Venturi disposed within said fluid conducting line adjacent the intake end, and means for directing a flow of gas through said Venturi away from said intake end toward said downstream end to produce a negative pressure upstream from said Venturi, the improvement comprising said evacuation apparatus in combination with a dental unit having a Waste line; a separator device, means on a lower portion of said separator device connecting it to said waste line, means on an upper portion of said separator device connecting it to the downstream end of said fluid conducting line, an exhaust air filter mounted on the upper portion of said separator device, a solids collector screen disposed in said lower portion of said separator device, and means for detachably connecting said lower portion to said upper portion of said separator device.

5. Evacuation apparatus comprising a fluid conducting line having an intake end and a downstream end,

a Venturi disposed within said fluid conducting line ad- '2 jacent the intake end, and means for directing a flow of gas through said Venturi away from said intake end toward said downstream end to produce a negative pressure upstream from said Venturi; said means for directing a flow of gas through said Venturi comprising an actuating valve having a jet disposed in fluid communication with said fluid conducting line at the upstream end of said Venturi, and a gas supply line connected to said actuating valve; an intake nozzle detachably mounted at the intake end of said fluid conducting line and having an oridice open to the atmosphere, and means for producing a static suction at said orifice of no more than five inches of mercury and being capable of drawing an inflow stream of air of less than eight cubic feet per minute at atmospheric pressure through said orifice when said gas supply line discharges 2.6 cubic feet of gas per minute at pounds per square inch gage through said actuating valve.

References Cited UNITED STATES PATENTS 988,345 4/1911 Irgens 128-277 1,345,606 7/1920 Leonard 128-277 X 2,253,143 8/1941 Siegel 32-33 2,575,513 11/1951 Fox 128-277 2,900,978 8/ 1959 Johannisson 128-276 3,017,886 1/1962 Thompson 128-276 3,164,153 1/1965 Zorzi 32-33 2,191,717 2/1940 Jeffery 230- 2,605,043 7/ 1952 Stetser 23'0-95 2,846,710 8/1958 Haka 230-95 2,851,213 9/ 1958 Swallert 230-95 2,902,992 9/ 1959 Renvall 128-145 .7 3,143,109 8/1964 Gewertz 128-276 3,335,727 8/1967 Spoto 128-276 FOREIGN PATENTS 942,189 2/ 1949 France. 1,008,125 5/1952 France.

CHARLES F. ROSENBAUM, Primary Examiner.

U.S. Cl. X.R. 

